Hydraulic motor with tachometer shaft



Feb. 2, 1965 A. R. GRAD HYDRAULIC MOTOR WITH TACHOMETER SHAFT Filed May 12, 1961 United States Patent Oil-ice 3,1h3ll9 Patented Feb. 2, 1965 3,163,009 HYDRAULIC MTR WITH TACHMETER HAFT This invention relates to a hydraulic motor and more particularly to an angle type of hydraulic motor provided with an auxiliary shaft that is separate from a power output shaft.

Angle type hydraulic motors have a positive displacement provided by axially arranged pistons in a rotatable cylinder barrel whose axis is inclined to the axis of an output shaft that receives torque from the pistons. The output shaft is adapted to drive a load device and may include a gear means for driving an auxiliary device such as a tachomcter device or a metering hydraulic pump frequently employed in a control circuit for a hydraulic system.

According to the present invention, an auxiliary shaft is provided that is separate from the load shaft or output shaft. The auxiliary shaft is directly connected to the cylinder barrel and adds to the load on a universal joint that couples the cylinder barrel to the load shaft. A load limitation on the auxiliary shaft must be within the additional load capacity of the universal joint; nevertheless, it is an object of the invention that an auxiliary shaft which adds to the load on the universal joint be employed to provide an economical and convenient means for driving an auxiliary device.

Another object of the invention is to provide an angle type of hydraulic motor having a cylinder barrel rotatable on a live axle whose inner shaft is rotatable with the cylinder barrel for driving an auxiliary device.

Another object of the invention is to provide an angle type of hydraulic motor, in which a cylinder barrel is coupled to a load shaft by a uniform velocity joint, with an auxiliary shaft directly connected to the cylinder barrel and available for driving an auxiliary device.

Another object of the invention is to provide an angle type of hydraulic motor with an auxiliary shaft directly connected to the cylinder barrel and presenting a free end for coupling to an auxiliary device at an end of the motor opposite to its load shaft end.

Other objects and advantages of the invention will be apparent from the following description and` accompar1ying drawings, in which:

l is a plan view in cross section of an angle type hydraulic motor embodying the invention;

FIG. 2 is a view taken along the line 2 2 of FIG. 1. FlG. 3 is a cross sectional view taken along the line 3- 3 of FlG. '2. FiG. 4 is a view on enlarged scale of a portion of an auxiliary shaft and a spline connector of PG. l shown separated for purpose of clarity.

Referring to the drawings, the angle type hydraulic motor 6 embodying the invention is a positive displacement type and comprises a two part housing having annular housing portions 7, secured together in angular relation. An end head 9 is secured to the end of housing '.7 and serves as a manifold having main passages 11, 12 leading to the ports for the supply and discharge of hydraulic fluid.

The housing portion 7 and the manifold 9 serve as a yoke structure that includes a live axle that extends through the manifold. The live axle comprises a bearing shaft 13 for rotatably supporting a cylinder barrel. The bearing shaft 13 is press fit within a shaft bore through the manifold and is further secured against movement by a spacer flange 14 suitably keyed thereto.

The spacer flange 14 is rigidly secured to the end face of the manifold block by socket head screws 16. A removable cover 17 is secured by screws 18 to the spacer flange 14 to enclose the outside end of the bearing shaft which includes a rotatable auxiliary shaft 19 further described herein.

A cylinder barrel 29 is supposed on a pair of axially spaced bearings 21, 22 disposed on the bearing shaft 13 and constructed and arranged to rotatably support the cylinder barrel 20 in an axially xed relation to the bearing shaft. The cylinder barrel 20 has a plurality of circumferentially spaced cylinder bores 23 generally parallel to the axis of rotation, and each cylinder bore 23 contains one of the pistons 24 which are connected by articulated connecting rods 26 to a flange 2S of a power output shaft 27' adapted for connection to a load device.

utput shaft 27 is journalled in radial bearings 31, 32 and in thrust and radial bearings 33 disposed in housing portion S. Output shaft 27 makes an angle with the axis of rotation of the cylinder barrel 20 which determines the stroke of the pistons 24. The shaft flange 23 receives thrust through the connecting rods 26 which are secured thereto in ball and socket connections in a plane transverse to the output shaft and through a point of intersection of the axis of the output shaft with the axis of the cylinder barrel 2t?.

A uniform velocity joint represented by a shaft 34 couples the output shaft 27 to the cylinder barrel 20 for rotating the cylinder barrel synchronously with the output shaft. The uniform velocity joint 34 comprises a pair of universal joints 3d, only one of which is shown, with its outer member secured by pins 37 to the cylinder barrel Ztl; and the other one of the universal joints, not shown, is similarly secured within a bore in power shaft 27 in a known manner.

The live axle comprising bearing shaft 13 includes the auxiliary shaft 19 disposed in concentric relation within bearing shaft 13. A roller bearing 38 secured within a counterbore in the outer end of the bearing shaft 13 rotatably supports a free end of the auxiliary shaft 19. The opposite end of the auxiliary shaft is coupled directly to the cylinder barrel 2d by means of a splined collar 39. The splined collar 39 is secured to the cylinder barrel 2t) by the pins 37 which secure the outer member of the universal joint 36 so that the collar 39 presents female splines 41 that receive the splined end 42 of the auxiliary shaft 19 for supporting it concentrically within the bearing shaft 13 for rotation with the cylinder barrel 2li. The leading ends of the interleaved splines are tapered to facilitate insertion of the auxiliary shaft 19 into the splined collar 39.

The free end of the auxiliary shaft is provided with a slot 43 or keyway for coupling in a known manner to an auxiliary device such as a signal producing hydraulic or electric tachometer, not shown.

The ports of the motor are adapted for connection to a source of fluid pressure and to a return such as the discharge and return ports of a variable displacement hydraulic pump, not shown, so that the pump and motor provide a variable speed transmission as is well known. The motor ports lead to the manifold passages 11, 12 respectively. One group of axial passages 44 in the manifold, FIG. 3 communicates with manifold passage 11 and each aligns with a separate through passage 47 in a distributor -to an arcuate port 4S in the working face of the distributor, which as shown is an axially floating flat valve i6 secured against rotation by a pin 49 extending into the manifold 9. Another group of axial passages 45 in the manifold 9 communicates with manifold passage 12 and each aligns with a separate through passage S1 in the flat valve 46 to the other arcuate port 52 in the face thereof.

The cylinder barrel 2t) is shown provided with a wear plate 53 secured on the end face thereof for rotation with the cylinder barrel. The wear plate 53 has ports or axial holes S4 serving as cylinder ports each in alignment with corresponding axial passages 25 to the cylinder bores 23.

These cylinder ports 54 in the wear plate alternately register with the opposite arcuate ports 4S, S2 in the face of the fiat valve 46 as the cylinder barrel rotates, and

thereby alternately supply pressure fluid to the cylinder bores 23 and exhaust uid therefrom so that the pistons 24 being displaced by motive iluid transmit torque to the output shaft 27 causing it to rotate. The uniform velocity joint 34 coupled to the cylinder barrel rotates the cylinder barrel with the output shaft and there rotates the auxiliary shaft 19 which is directly connected to the cylinder barrel.

Holdup pistons 56, FIG. 3, Vare disposed in the back face of the flat valve 46 in alignment with its through holes 47, 51 and in alignment with the axial holes 44, 45

in the manifold 9. The holdup pistons 56 lare sleeves f normally urged by springs 57 against the face of manifold 9 and, the springs 57 normally urge the flat valve 46 against the face of the wear plate 53. When motive fluid is suppled to the motor 6, the hydraulic pressure in each arcuate port 48, 52 tends to separate the flat valve from the wear plate; but the holdup pistons 56 being subject to the pressure in their associated arcuate ports hold ,the at Valve 'in fluid tight relation with the rotating wear plate 53, and the pressure holds the holdup pistons 56 `in sealing engagement with the manifold so that fluid is conducted between the manifold and the flat valve without leakage.

Bridge pistons S are shown in FIGS. 1 and 2 as located in the back face of the flat valve intermediate the arcuvention has been shown md described, other embodiments and modifications may be made within theV spirit of the invention and the scope of the appended claims.

I claim: l. In a hydraulic positive displacement angle motor comprising a stationary housing having a first end and a second end, a relatively high torque power output drive shaft rotatably supported by a plurality of bearings in said rst end of said housing so as lto be radially and axially rigid therewith, a bearing axle rigidly secured in said second end of said housing and extending axially inward therefrom at a fixed angle to the axis of said power output drive shaft, a cylinder barrel, bearing means within said cylinder barrel for rotatably supporting said cylinder barrel on said bearing axle in radially and axially rigid relation thereto within said housing, a plurality of cylinder bores and cylinder ports in said cylinder barrel generally parallel to the axis thereof, said cylinder rbores containing pistons connected by articulated connecting rod means to the power output drive shaft for transmitting all of its output torque, said second end of said housing-serving as a manifold 'for motive fluid supply and discharge passages, a distributor valve non-rotatably mounted on said manifold between said manifold and said cylinder barrel and having a pair of arcuate ports with which said cylinder ports alternately register as said cylinder barrel rotates, an improvement comprising said bearing axle being hollow andv an auxiliary shaft extending through said bearing axle, means connecting an axially inner end of said auxiliary shaft to said cylinder barrel for rotation therewith, means rotatably supporting an axially outer end of said auxiliary shaft within said bearing axle, whereby said auxiliary shaft is in eect an extension of thek cylinder barrel through the housing that rotatably supports the cylinder barrel radially of the cylinder barrel, and said auxiliary shaft is adapted for connection to an auxiliary device for supplying only a relatively smallftorque thereto.

2. The angle type motor defined in claim 1 in whichv the auxiliary shaft is coupled to said cylinder barrel by means of a flange secured to said cylinder barrel and providing a female spline and said auxiliary shaft having a cooperating splined end, whereby said auxiliary shaft may readily be inserted into said bearing axle for coupling with said cylinder barrel to provide the auxiliary low torque drive.

References Cited by the Examiner UNITED f STATES PATENTS 1,087,861 `2/14 Alexander et al. 121-62 1,203,165 10/16 VWilliams et al. `103162 1,673,632 6/28 Mattson 123-43 2,146,133 2/39 Tweedale 10S-162 2,177,008' 10/39 Snader et al. 103-162 2,313,407 3/43 Vickers et al. 103-162 2,525,979 10/50 Vickers 10S-162 2,699,123 1/55V Bonnette et al. 103-162 2,737,899 3/56 Bonnette et a1. 10S-162 2,975,597 3/61 Arz 103-162 JOSEPH H. BRANSON, JR., Primary Examiner.

KARL I. ALBRECHT, FRED E. ENGELTHALER, Examiners. 

1. IN A HYDRAULIC POSITIVE DISPLACEMENT ANGLE MOTOR COMPRISING A STATIONARY HOUSING HAVING A FIRST END AND A SECOND END, RELATIVELY HIGH TORQUE POWER OUTPUT DRIVE SHAFT ROTATABLY SUPPORTED BY A PLURALITY OF BEARINGS IN SAID FIRST END OF SAID HOUSING SO AS TO BE RADIALLY AND AXIALLY RIGID THEREWITH, A BEARING AXLE RIGIDLY SECURED IN SAID SECOND END OF SAID HOUSING AND EXTENDING AXIALLY INWARD THEREFROM AT A FIXED ANGLE TO THE AXIS OF SAID POWER OUTPUT DRIVE SHAFT, A CYLINDER BARREL, BEARING MEANS WITHIN SAID CYLINDER BARREL FOR ROTATABLY SUPPORTING SAID CYLINDER BARREL ON SAID BEARING AXLE IN RADIALLY AND AXIALLY RIGID RELATION THERETO WITHIN SAID HOUSING, A PLURALITY OF CYLINDER BORES AND CYLINDER PORTS IN SAID CYLINDER BARREL GENERALLY PARALLEL TO THE AXIS THEREOF, SAID CYLINDER BORES CONTAINING PISTONS CONNECTED BY ARTICULATED CONNECTING ROD MEANS TO THE POWER OUTPUT DRIVE SHAFT FOR TRANSMITTING ALL OF ITS OUTPUT TORQUE, SAID SECOND END OF SAID HOUSING SERVING AS A MANIFOLD FOR MOTIVE FLUID SUPPLY AND DISCHARGE PASSAGES, A DISTRIBUTOR VALVE NON-ROTATABLY MOUNTED ON SAID MANIFOLD BETWEEN SAID MANIFOLD AND SAID CYLINDER BARREL HAVING A PAIR OF ARCUATE PORTS WITH WHICH SAID CYLINDER PORTS ALTERNATELY REGISTER AS SAID CYLINDER BARREL ROTATES, AN IMPROVEMENT COMPRISING SAID BEARING AXLE BEING HOLLOW AND AN AUXILIARY SHAFT EXTENDING THROUGH SAID BEARING AXLE, MEANS CONNECTING AN AXIALLY INNER END OF SAID AUXILIARY SHAFT TO SAID CYLINDER BARREL FO ROTATION THEREWITH, MEANS ROTATABLY SUPPORTING AN AXIALLY OUTER END OF SAID AUXILIARY SHAFT WITHIN SAID BEARING AXLE, WHEREBY SAID AUXILIARY SHAFT IS IN EFFECT AN EXTENSION OF THE CYLINDER BARREL THROUGH THE HOUSING THAT ROTATABLY SUPPORTS THE CYLINDER BARREL RADIALLY OF THE CYLINDER BARREL, AND SAID AUXILIARY SHAFT IS ADAPTED FOR CONNECTION TO AN AUXILIARY DEVICE FOR SUPPLYING ONLY A RELATIVELY SMALL TORQUE THERETO. 